Improved composition for moulds and cores for casting- metals



waisted States patent Gtjijiw.

CHARLES GBASSER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOB TO METALLICCOMPRESSION CASTING COMPANY, OF BOSTON, MASSACHUSETTS.

team Patent No; 90,257, dated May 18, 1869.

The Schedule referred to in MGLGMCBIB Patent and making part 0! tho m T0 all whom at may concern:

Be it known that LCHARLEs Grmssnu, of the city and county ofPhiladelphia, and State of Pennsylvania, have invented a new and improv(1 Composition for Moulds and Cores for Casting Md als; and I do here--by declare the following tube a full, clear, and exact description ofthe same.

The subject of this invent-ion is a composition for the Manner ofMixing, and Use in Application.

Take one part of marble pieces, ground to dust, one part of clean sand,one part of plaster of Paris, audone part of lamp-black. All are groundtogether to a fiue powder.

For the marble-dust and sand may be used an equivalent substance, whichmay be had at any mill where marble blocks are sawn, and which isproduced by saw and sand cutting the marble block.

' The above-described composition ismixed with water in the same manneras plaster of Paris is used, when cast. It is poured over the wax, ormetallic pattern, and when set and hardened, which will take place inabout half an hour, the pattern may be taken out. The proper gates andsprues are cut in the same mannor as by sand-moulding, and the mould isready for burning.-

. The nature of the composition is such, that it may be put into greatheat at once, without injury, or cracking. When the moulds are broughtto red heat, they are kept so for severai "more, and then the furnacemust cool gradually, as too sudfen exposure of the moulds to cold airwill crack them. When the moulds are cooled, they are placed between twoplates, held together by screws, or clamps, in manner like sand moulds,and the metal is poured in, asin ordinary casting. The bronze and brass,or copper castings made in such moulds are far superior to sandmouldcastings, sharper and smoother.

One great advantage of this compositon is, its applicability to coresand undercut castings, where a wax pattern is employed and melted out;the composition will not be washed, or injured in the least by themeltingwax.

Having thus described my invention,

The following is what I claim, and for which I desire to secure LettersPatent:

A composition of the specified materials, in proportion about the same,or their chemical equivalents, to be used for making moulds and cores,used in casting metals.

CHARLES GRASSER.

Witnesses:

JOHN Jos. OH. SMITH, MICHAEL SMITH.

